Seals and methods and means of sealing for rotary engines and the like

ABSTRACT

A sealing assembly for providing a sliding seal between two members, such as the housing and rotor of a rotary engine. A groove is formed in one member and extends substantially transversely of the direction of movement of that member relative to the other member. The seal blade is received in the groove and has a tip portion which projects from the groove for sliding, sealing engagement with a surface of the other member. Cooperating cam surfaces are provided on the trailing side wall of the groove and the trailing side surface of the seal blade which are operable in response to forces urging the trailing side surface into contact with the trailing side wall to produce reaction force components urging the blade to extend from the groove. Coupling seal recesses are formed at opposite ends of the groove, and a coupling seal member is received in each of the recesses. The coupling seal member and seal blade are interengageable with each other in such a manner that the coupling seal members are urged to project axially from the respective coupling seal recesses while simultaneously urging the seal blade toward a centered position in the groove and to extend from the groove.

United States Patent [191 Bibbens Jan. 14, 1975 SEALS AND METHODS ANDMEANS OF SEALING FOR ROTARY ENGINES AND THE LIKE [76] Inventor: WilliamH. Bibbens, 16500 N. Park Dr., Southfield, Mich. 48075 [22] Filed: May3, 1973 [21] Appl. No.: 356,885

[52] US. Cl 418/61 A, 418/113, 418/120, 418/122, 418/142 [51] Int. CL...F0lc 19/02, F04c 15/00, F040 27/00 [58] Field of Search 418/61 A, 113,119124, 418/142, 237; 227/168 [56] References Cited UNITED STATESPATENTS 1,831,243 11/1931 Hart et al 418/237 3,127,095 3/1964 Froede 1418/121 3,142,439 7/1964 Froede 418/61 A 3,180,560 4/1965 Paschke418/124 3,180,561 4/1965 Paschke 418/120 3,204,615 9/1965 Starmuehler418/113 3,206,108 9/1965 Abermeth 418/91 3,261,334 7/1966 Paschke418/123 3,485,217 12/1969 lrgens 418/121 FOREIGN PATENTS OR APPLICATIONS626,596 5/1927 France 418/122 993,574 5/1965 Great Britain 418/1221,154,315 9/1963 Germany 418/142 Primary Examiner-John J. VrablikAttorney, Agent, or FirmReising, Ethington & Perry [57] ABSTRACT Asealing assembly for providing a sliding seal between two members, suchas the housing and rotor of a rotary engine. A groove is formed in onemember and extends substantially transversely of the direction ofmovement of that member relative to the other member. The seal blade isreceived in the groove and has a tip portion which projects from thegroove for sliding, sealing engagement with a surface of the othermember. Cooperating cam surfaces are provided on the trailing side wallof the groove and the trailing side surface of the seal blade which areoperable in response to forces urging the trailing side surface intocontact with the trailing side wall to produce reaction force componentsurging the blade to extend from the groove. Coupling seal recesses areformed at opposite ends of the groove, and a coupling seal member isreceived in each of the recesses. The coupling seal member and sealblade are interengageable with each other in such a manner that thecoupling seal members are urged to project axially from the respectivecoupling seal recesses while simultaneously urging the seal blade towarda centered positionin the groove and to extend from the groove.

43 Claims, 49 Drawing Figures PATEHTEB JAN 1 4 I975 SHEET Ul0F15PATENTED 3,860,365

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sum DSOF 1s PATENTED 3.880.365

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SHEET 120! 15 "I\\ Z5 FIRlNG POSITION EXHAUST \j INTAKE (TM a fi m 2;

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SHEEI 1% HF 15 STA RT 0 F COM P RESSION START OF COM PRESSION EXPNSION FEXHAkJST 74 STA ESgIEN COMP PATENTEI] JAN I 4I975 SHEEI 15 0F 15 NEARPEAK OF COMPRESSION F. OE M mT Am I S EXHAUST POSITION EXHAUST K +T\NEAR PEAK OF \RESSION /#Z 4 ST NIT COMP a zze g 7 40 N EA R PEAK OFCOMPRESSION INTAKE YF\ zxa SEALS AND METHODS AND MEANSOFSEALING FORnoranr ENGINES AND THE LIKE This invention relates generally to sealsand methods and means of sealing as related to rotary machines and isparticularly concerned with seals and means of sealing for relativelymoving parts of eccentric rotor engines of the type commonly referred toas Wankel engines although the invention is not restricted to eccentricrotary engines and will have application to other types of machines,pumps, compressors and the like.

While the problem will be generally discussed below in connection withrotary engines of the Wankel type, the present invention is concernedwith any device wherein it is necessary to provide slidable seals foruse with moving pressure chambers, wherein the chambers are defined bytwo or more relatively moving members. Moreover, the invention in itsbroadest aspects is concerned with confining gases or fluidsbetween atleast two zones of different pressures, and more specifically, withproviding, by a sealing means and control features resistant toundesirable flow of gas or fluid from a high pressure zone to a lowpressure zone between at least two relatively moving members Therefore,the phrase rotary engines and the like as used herein refers not only toeccentric rotor engines of the Wankel type, but to any device havingrelatively movable members wherein it is necessary to provide slidableseals between the relatively movable members to confine fluids betweentwo or more zones of differential pressures.

Eccentric rotor engines are engines of the type wherein a rotor(sometimes referred to as a rotary piston") is eccentrically mountedwithin an enclosed cavity of a housing and is rotatable about its ownaxis, which axis is eccentric to a rotatable main shaft axis, the mainshaft being mounted in the housing. The rotor cooperates with the cavitywalls to define a plurality of chambers that expand and contractvolumetrically as the rotor rotates within the cavity, and therebyprovide the four phases of intake, compression, expansion (or ignitionand expansion) and exhaust, to transmit power. The most commonly knowneccentric rotor engine (not claimed as a part of this invention) is thetype disclosed in U.S. Pat. No. 2,998,065 of Wankel et al. The Wankelengine includes a housing having a cavity having a surface which iscommonly referred to as a trochoidal surface, and will be so referred toherein. A rotor which may be of substantially triangular configuration,or of other configurations, is received in the cavity. The rotor has endfaces extending transversely to its rotary axis, and has convex orformed sides extending between its apices. Each of the sides of therotor cooperate with the trochoidal surfaceof the cavity to define achamber, the walls of each chamber being defined by the trochoidalsurface of the cavity, one of the convex or formed sides of the rotor,and the end walls of the housing that extend transversely to thetrochoidal surface.

A difficult problem with rotary engines of the type discussed in thepreceding paragraph is that of maintaining reliably effective sealingbetween chambers to contain variable and different pressures, whichchambers are defined as the rotor rotates about an axis within thehousing. Reliable seals must be provided between the end faces of therotor and the opposing end wall surfaces of the housing as well asbetween the apex portions of the rotor and the trochoidal surface of thehousing. In conventional rotary engines of this type, the apex portionsof the rotor member are provided with apex seals that are slidablymounted in retaining grooves in the rotor, the retaining grooves havingsides machined ina predetermined angular relationship with radial linesthat extend from the axis of the rotor to each apex of the rotor sothat, each apex seal moves outwardly and inwardly within its retaininggroove as it sweeps along the trochoidal surface with which it isslidingly engaged. Side seals are provided within the opposite end facesof the rotor and extend between the apex portions of the rotor. The sideseals engage the surfaces of the end walls of the cavity fixed to therotor housing. In order to seal the ends of the apex portions of therotor, coupling seals are slidably mounted within the end faces of therotor for axial movement in a direction parallel to the axis of therotor. The coupling seals also serve as a junction seal between the sideseals and apex seals. The ends of the side seals abut the couplingseals, and theapex seals are received in grooves formed in the couplingseals. The coupling seals are conventionally of cylindrical shape andare received in cylindrical openings formed radially inwardly of therespective apices of the rotor. The coupling seal face seats against theadjacent end wall surface of the rotor housing and sweeps along suchsurface in a trochoidal path having generally the same configuration asthe trochoidal surface of the cavity as the rotor rotates within thecavity. 7

In present constructions, the coupling seals, side seals, and. the apexseals are resiliently biased toward engagement with the respectivesurfaces against which they are toseal. It is important that each apexseal, side seal and coupling seal always remain in contact with theirrespective sealing surfaces; however, the seals should be. freelymovable with respect to rotor in order to accommodate surfaceirregularities due to manufacturing tolerances, heat distortions, wear,etc, and so that the seals will always be free for quick return movementto maintain coactive contact with theirrespective sealing surfaces ifcaused to move out of contact therewith by adverse forces. If an apexseal is caused to move out of contact with the trochoidal surface, anyfrictional forces tending to retard its return movement to sealingengagement with the trochoidal surface increases the amount of leakageand thus decreases the power of the engine, wastes fuel, and causes theloss of emissions control. Similarly, if a coupling seal is caused tomove out of engagement with the end wall surface of the chamber, anyfrictional forces tending to retard its return movement to sealingengagement with the end wall surface increases (1 the amount of leakageand hence the loss of power, (2) high fuel consumption, and (3) the lossof emissions control. Further, if a side seal member is caused to moveout of engagement with the end .wall surface of the chamber, anyvundesirable frictional forces which would retard its return movement toits sealing engagement would cause leakages from its respective chamber,allowing loss of power, loss of emissions control, and waste of fuel.

With the conventional seal arrangement described in the precedingparagraphs, adverse forces exerted on the various sealing components asthe rotor rotates within the trochoidal cavity tend to increaseundesirable frictional contact between the apex seal, coupling seal,side seal members and apex seal grooves to thereby retard free movementof the seals with respect to their sealing surfaces. Furthermore, theconstantly changing accelerating forces acting on the apex seals due tothe eccentric motion of the rotor and the trochoidal path of the apexseals tend to aggravate and cause undesirable frictional engagement andretard return motion of the seals when they are forced out of engagementwith their respective sealing surfaces. It is believed that theseundesirable conditions are further aggravated by the impact forces onthe apex seals defining the ends of the ignition chamber upon firing dueto the sudden increase of pressure which tends to force the sealsradially outwardly into engagement with the trochoid surface with anamount of pressure that unduly increases the friction forces between theapex seal blades and the trochoidal surface, and that increases thelikelihood of the blade coming out of contact with the trochoidalsurface when the direction of the blade changes abruptly as is necessarydue to the configuration of the path of movement of the apex seal blade.The intermittently high unit load pressure exerted on the apex sealblade also increases the likelihood of fatigue, damage, wear, anddistortion to the trochoidal surface of the housing, reducing the lifeof the engine and of the apex seal, further contributing to inadequate,unreliable and unstable sealing conditions.

It is, therefore, an object of this invention to provide a constructionwith a sealing means between relatively movable members of a rotaryengine and the like wherein the differential in the contact pressurebetween the surfaces of the seal members and the surfaces with which theseal members are engaged during each cycle of operation of the rotaryengine or the like is minimized without losing sealing effectiveness.

A further object is to provide a construction with a sealing means thatwill produce a sliding seal between two members of rotary engines andthe like, one of which members moves relative to the other, wherein aseal blade is received in a groove in said one member, the grooveextending substantially transversely of the direction of relativemovement between the two members, in which cooperating cam surfaces areprovided between the groove and the seal blade, which cooperating camsurfaces are coactively responsive to forces urging the seal blade intocontact with one of the side walls of the groove in such a manner as toproduce advantageousreaction force components urging the seal blade toslidably cam itself outwardly from the groove to thereby maintainsealing engagement with the surface of the other member.

A further object is to provide a component sealing construction with aprovision for a sealing means that will minimize the adverse effects offriction force between the drive wall of the groove and the trailingside surface of the seal blade.

A further object is to provide an apex sealing arrangement for rotaryengines and the like that will minimize the shock loading on the apexseal blade caused by the intermittent and instantaneous pressure rise atignition and explosion of the fuel without reducing the sealingefficiency of the apex seal.

Still another object of this invention is to provide an apex sealingarrangement for rotary engines and the like that will (I) increase thepower output by minimizing leakage from zones of relatively highpressure to zones of relatively low pressure, (2) provide better controlof the content of the exhaust emissions by reducing the amount ofunburned fuel in the emissions caused by leakage during the ignition andexpansion phase of each cycle of the engine, (3) provide for greaterefficiency of operation by reducing the fuel consumption withoutsacrificing power output, and (4) reduce the wear of the sealingcomponents and of the housing and thereby provide a longer operatinglife for the sealing components and housing.

Another object of this invention is to provide an apex sealingarrangement for rotary engines and the like wherein friction forces thatwould normally tend to retard movement of the sealing members producecompensating reaction forces tending to urge the sealing members to movein a sealing direction without retardation.

A further object is.to provide an apex sealing ar rangement for rotaryengines and the like wherein the high pressures on the apex sealsproduced by ignition of the fuel are redistributed to reduce the impactforces on the individual seals and thereby decrease the wear on therelated engine parts.

A further object of this invention is to provide an apex seal assemblyfor rotary engines and the like including a retaining member with whichthe apex seal and coupling seal can be assembled together and calibratedand the entire assembly installed as a unit on the rotor of a rotaryengine or the like.

A still further object is to provide an apex seal assembly for rotaryengines and the like having an apex seal blade and a coupling sealmember wherein the apex seal blade and coupling seal have coactingsurfaces operable to produce desirable reaction components of force inresponse to forces ordinarily adverse to the sealing function of theassembly, which reaction component increase the sealing function of theassembly.

A still further object is to provide a rotor for a rotary engine or thelike wherein the apex portions of the rotor are defined by a retainingmember that is installed separately onto the rotor so that side sealgrooves can be more easily cut into the rotor prior to installation ofthe retaining member.

A further object is to provide a rotor for a rotary engine or the likewherein the apex portions of the rotor are defined by a retaining memberthat is installed separately onto the rotor and which can be made of amaterial different from but compatible with the material of the rotor sothat the retaining member does not have to meet the requirements of therotor material in addition to the requirements of the material of theretaining member.

A further object is to provide a retaining member for installation ontothe rotor of a rotary engine or the like to form an apex portionthereof, the retaining member being formed with slots for receiving theends of side seal strips with a clearance being provided between thesurface of the slots and the ends of the side seal strips to eliminateadverse friction forces between the side seal strips and retainingmember and at the same time provide a baffling effect for the escapementof fluid pressure around the ends of the side seal strips withoutretarding movement of the coupling seals.

Still another object is to provide a rotor for a rotary engine or thelike having side seals, coupling seals and apex seals wherein thecoupling seals do not frictionally engage the side seals so that theside seals and coupling seals do not interfere with the scalingfunctions of each other, and wherein the coupling seals and apex sealsare coactively engageable with each other to urge each other towardsealing engagement with their respective sealing surfaces.

A still further object is to provide a seal blade for the apex of therotor of a rotary engine or the like wherein the seal blade has a tipwith a working surface for slidable, sealing engagement with anothersurface wherein the trailing portion of the working surface has a largerradius of curvature than the leading portion thereof, and which trailingportion of the blade tip is levered in the manner of a bell crank toalways assure contact with the trochoidal surface of the housing and toaccommodate changes in the trochoidal surface due to heat, forcedistortion, manufacturing tolerances, and changes in the contour of thesurface engaged thereby.

A further object is to provide a seal blade for the apex of a rotaryengine or the like having a cam surface formed on the trailing surfacethereof for coactively engaging the trailing side wall of the groove inwhich it is adapted to be received in sucha manner that the seal bladeis urged in a direction towardthe trailing side wall and outwardly ofsuch groove.

Another object is to provide a seal blade for the rotor of a rotaryengine or the like having a coupling seal cam surface formed thereon forcoactively engaging a coupling seal member in such a manner that theseal blade and coupling seal are urged toward sealing engagement withtheir respective sealing surfaces by their coactive engagement.

A further object is to provide a coupling seal member for a rotaryengine or the like having a cylindrical body formed with a groove forreceiving an end portion of an apex seal blade, and having a seal bladecontact member for coactively engaging a cam surface formed on such sealblade to produce constant reaction compo nents of force urging thecoupling seal toward engagement with the surface it is adapted tosealingly engage.

A further object is to providev a sealing construction and means ofsealing for rotary engines and the like that will constantly urgeoutward radial forces and axial forces to resist inwardforces of thesealing members when saidsealing members are cooperating. with sealingsurface of the non-retaining seal members throughouteach completerevolution of the rotating member.

Another object is to provide freely slidable sealing members for rotaryengines and the like to constantly resist forces and friction that wouldotherwise retard the sealing members free movement in an. outwarddirection toward the sealing surface with which they coactivelycooperate.

A further object is to provide a. sealingconstruction for rotaryenginesand the like that will redirect forces to contribute towardconstant sealing direction. of said seals to. maintain engagementwiththe sealing surfaces irrespective of the positionthat the rotatingmember takes throughout each revolution about an eccentric axis.

A further object is to decrease the high load pressures on theworkingsealing surfaces of the seals of rotary engines and the likewhile providing free movement of the slidable. members without losingsealingeffectiveness or proper sealing between the seals and thecooperating members.

A further object is to provide. an assembly including a pair ofoppositvely extending side sealslots in said coupling seal member, eachof said coupling seal side seal slots being positioned in alignment witha respective one of said side seal slots in said retaining member toform an extension thereof, the respectiv e end portions of said sideseal strips being received in'the's'lots in said coupling seal member,and wherein a clearance is always maintained between the end portionsofsaid side seal strips and the surfaces of the respective-side sealslots in said coupling seal members in all positions of said couplingseal member. Y

The foregoing, and further objects, are achieved in the presentinvention by the provision of an apex ing assembly including an apexseal blade retaining member, an apex seal blade and a pair of oppositehand coupling seal members biased outwardly by springs. The retainingmember may consist simply of the apex portion of the rotor for therotary engine, or may be a separate member that can be installedseparately onto the rotor to define the apex portion thereof. Theretaining member is formed with a groove for receiving the apex sealblade, and a pair of coupling seal recesses at each end whichcommunicate with the apex seal blade groove. The coupling seal member isformed with a contact arm that responds to frictional forces between thecoupling seal and the end wall of the cavity in which the rotor isreceived to urge the apex seal blade toward the trailing side wall ofthe slot in which it is received. The apex seal blade is formed with camsurfaces on its leading side surface for engagement by the contact armsof the coupling seals to bias the coupling seals axially outwardlytoward engagement with each end wall, surface of the cavity. The ends ofthe apex seal blades are relieved on their lower portions so that anyintermittent contact with the end wallzsurfaces ofthe engine, cavity bythe ends of the seal blade will produce forces further maintaining theapex seal blade in sealing en-. gagement with its sealing surfaces. Thetrailing side wall of the slot in which the seal blade is received isformed-with a cam surface, and the trailing sidesurface through ports inthe apex seal assembly, and operate to.

control and limit the maximum pressure caused by ignition to reduce theimpact forces on the seal blade's'at ignition to reduce distortion ofthe trochoid surface of the housing and simultaneously reduce wear onthe co operating members.

Other objects, advantages and features of the, invention will becomeapparent from the following description taken in connection with theaccompanying drawings in which:

FIG. 1 is a perspective view of a rotary engine rotor? and trochoidalchamber having a prior art, conventional apex sealing arrangement;

FIG. 2 is a diagram illustrating the distribution of the radial forcesexerted by the apex seal on the trochoidal surface of the engine cavity,the FIG. 2 diagram illustrating the forces exerted by conventional apexseal assemblies, and one typifying a more desirable force pattern, aswell as the theoretically ideal force pattern;

FIG. 3 is a view of a rotary engine diagrammatically illustrating thevarious positions and conditions affecting the apex seal during rotationof the rotor; 1

FIG. 4 is a graphical illustration ofthe velocity variations of each ofthe apex seals during rotation of the rotor;

FIGS. 5A and 5B are graphic illustrations illustrating the apex sealvelocity change in relationship to the change of the rake angle of theapex seal with respect to the surface of the engine cavity;

FIGS; 6A-6E are fragmentary sectional views of an apex seal of ,theengine of FIG. .1 illustrating the change in the position and conditionsof the sea] as the seal moves along the surface of the cavity of theengine from the lefthand firing position to the right-hand firingposition;

FIGS. 7 and 8 are elevational views of a typical rotary engine rotor andtrochoidal chamber of the type illustrated in FIG. 1 showing thepositions of the rotor creating adverse sealing conditions at the apexseal blades;

FIG. 9 is an elevational view of a rotary engine rotor and trochoidalchamber, the rotor having apex seal assemblies according to one form ofthe invention;

FIG. 10 is an enlarged elevational view of an apex seal assembly of theengine of FIG. 9;

FIG. 11 is a side view, on a slightly reduced scale, of the sealingassembly of FIG. 10 taken on lines llll;

FIG. 12 is a view on lines 12l2 of FIG. 11;

FIG. 13 is a sectional view taken on lines l313 of FIG. 10;

FIG. 14 is a view similar to FIG. 10 on an enlarged scale;

FIG. 14A is a sectional view, on an enlarged scale, taken on lines14A14A of FIG. 11;

FIG. 14B is a view illustrating the manner in which an apex sealaccording to the present invention tends to resist separation from thetrochoid surface and cooperating sealing surfaces due to skipping anddistortions in the trochoid surface as compared with one conventionalapex seal construction; FIGS. 15 through 19 are views similar to FIG. 10illustrating the change in. the position of the apex seal, couplingseal, and side seal, and illustrating sealing surfaces with the sidewalls of the trochoidal chamber as the seals move from the left-handfiring position to the right-hand firing position; FIG. 20 is aperspective view of the coupling seal and spring used with the assemblyof FIG. 10;

FIG. 21 is a perspective view of the apex seal blade used with anassembly of FIG. 10;

FIG. 22 is a perspective view of the apex seal retainer used with anassembly of FIG. 10;

FIG. 23 is a view similar to FIG. 10 of an apex seal assembly accordingto another embodiment of the invention;

FIG. 24 is a sectional view taken on lines 24-24 of FIG. 23;

FIGS. 25 and 26 are sectional views taken on lines 25-25 and 26-26,respectively, of FIG. 24;

FIG. 27 is a view similar to FIG. 9, partially in section. of a rotaryengine rotor-and trochoid housing according to another embodiment of theinvention;

. FIGS. 28, 29 and 30 areenlarged fragmentary views of each of theapexportions of the rotor of the engine of FIG. 27;

FIG. 31 is a view similar to FIG. 27 with the rotor in a differentposition;

FIGS. 32, 33 and 34 are enlarged fragmentary views of each of the apexportions 'of therotorin the position of FIG. 31;

FIG. 35 is a view similar to FIG. 27 with the rotor in still differentposition; v

FIGS. 36, 37 and 38 are enlarged fragmentary views of each of the apexportions of the rotor in the position of FIG. 35;

FIG. 39 is a view similar to FIG. 27.with the rotor in still anotherposition; and i FIGS. 40, 41 and 42 are enlarged fragmentary views ofeach of the apex portions of the rotor in the position of FIG. 39.

The numerous adverse forces and conditions acting on the apex seals ofWankel engines will first be described in connection with FIGS. 1through 8 in connection with conventional, prior, art apex sealingassemblies.

In FIG. 1, reference numeral 20 collectively designates a rotary enginehousing having a cavity 22 formed with a trochoidal surface 24 having aninwardly projecting upper lobe 28 and an'inwardly projecting lower lobe26. The cavity 22 has a central axis designated by reference numeral 21.The cavity 22 is further defined by the inner surfaces 27a and 29a ofend plates 27 and 29, respectively, closing the opposite ends of thecavity. Fragmentary portions of the end plates 27 and 29 are illustratedin FIG. 1. Intake and exhaust ports 23 and 25, respectively, areillustrated in the trochoidal wall 24 of the cavity on opposite sides ofthe lobe 26. In some conventional rotary engines and the like, theintake and exhaust ports are formed in the end plates rather than in thetrochoid surface.

Eccentrically rotatably mounted in the cavity 22 is a rotor collectivelydesignated by reference numeral 30, the rotor 30 being of triangularconfiguration with convex side walls. The axis of the engine housing andcavity 22 is indicated by reference numeral 21, while the axis of therotor is indicated by reference numeral 31. The rotor 30 includes an endface 32 disposed in opposed relationship with the surface 27a of the endplate 27, an end face 32 disposed in opposed relationship with thesurface 29a of the end plate 29, and three side walls 34, the side wallsbeing individually designated by reference numerals 34a, 34b and 340.The apex portions of the rotor are designated by references charactersX, Y and Z. The side wall 34b extends between the apex portions X and Y,the side wall 34c extends between the apex portions Y and Z, and theside wall 34a extends between the apex portions Z and X.

Mounted in the end face 32 and extending along each of the side wallsbetween the apex portions are side seal members 36, the side seals 36being designated individually by reference numerals 36a, 36b and 36cwhich are disposed adjacent to the side walls 340, b and c,respectively. The side seals 36 are provided to sealingly engage thesurface 27a of the end plate 27. The ends of the side seals engagecoupling seals 38x, 38y and 382 located at the apex portions X, Y and Z,respectively. Also mounted in the apex portions are are apex seal blades40, the apex seal blades being individually designated by referencenumerals 40x, y and z at the apex portions X, Y and Z, respectively.Similar side seals and coupling seals are provided on the end face 32 ofthe rotor'to sealingly engage the end face 29a. The apex sealv blades 40engage the trochoidal surface 24 and sweep along the surface 24 as therotor 30 rotates

1. A coupling seal member for a rotary engine or the like comprising: acylindrical body; a groove formed in said body and extending along thelength thereof; and a seal blade pressure member formed on said couplingseal member adapted to engage a seal blade at least partially receivedin said groove, said body having an outer end with an upper contactingsurface for sliding sealing engagement with a surface of another member,and a lower relieved surface inclined away from said contacting surface.2. A coupling seal member as claimed in claim 11 wherein said couplingseal member is formed with an extension arm projecting from saidcylindrical body on one side of said groove, said seal blade pressuremember being formed on said extension arm and being adapted to engage acoupling seal cam surface formed on an apex seal blade received in saidgroove.
 3. A seal blade for a rotary engine or the like adapted for usein a groove of a coupling seal member comprising: a tip portion with aworking surface defined thereon, said tip portion having a leading and atrailing edge, a trailing side surface extending from the trailing edgeof said tip portion, a leading side surface extending from the leadingedge of said tip portion, and a cam surface formed on said trailing sidesurface, said cam surface comprising a concave surface formed on saidtrailing side surface, further comprising a pair of coupling seal camsurfaces formed on the leading side surface of said seal blade, theouter ends of said seal blade each having upper and lower surfaces, thelower surfaces being relieved inwardly with respect to the uppersurfaces.
 4. A seal blade as claimed in claim 3 wherein the workingsurface of said outer tip portion has a leading portion and a trailingportion and an imaginary rake angle line intersects said tip portionsuch that the leading portion of said working surface is on one side ofsaid rake angle line and the trailing portion of said working surface ison the other side of said rake angle line, said leading portion having acurvature the radius of which has a center located substantially on saidrake angle line, said trailing portion having a curvature the radius ofwhich has a center located on the leading side of said rake angle line,the radius of curvature of said trailing portion being larger than theradius of curvature of said leading portion such that the trailingportion of the working surface extends further from said rake angle linethan the leading portion of said working surface.
 5. A seal blade asclaimed in claim 4 wherein said rake angle intersects the bottom surfaceof said seal blade at a location closer to said trailing side surfaceThan the said leading side surface.
 6. A rotor for a rotary engine orthe like of the type having a housing forming working chambers with arotor rotatable in the housing and having apex portions with grooves andapex seals received therein for engaging the wall of the housing to formthe working chambers and wherein the seal blades are loosely received inthe grooves to allow leakage into the grooves from the working chambers,said rotor comprising: a plurality of apex portions; a groove formed ineach of said apex portions extending substantially parallel to the axisof rotation of said rotor; a plurality of accumulator passages formed insaid rotor, the number of said accumulator passages corresponding to thenumber of said grooves; each of said accumulator passages having one endcommunicating with the leading side wall of the groove of one apexportion and its other end communicating with the trailing side wall ofthe apex portion adjacent to and trailing said one apex portion.
 7. Aseal blade for a rotary engine or the like comprising: a tip portionwith a working surface defined thereon, said tip portion having aleading and a trailing edge; a trailing side surface extending from thetrailing edge of said tip portion; a leading side surface extending fromthe leading edge of said tip portion; said trailing side surface beingformed with an upper concave cam surface and a lower convex portion;said leading side surface being concave substantially throughout itslength; and outer ends extending between said leading and trailing sidesurfaces, said outer ends each having an upper surface adjacent therespective tip portions, and a lower surface depending from said uppersurface and relieved with respect to said upper surface.
 8. A sealingassembly for providing a sliding seal between two members, one of whichmembers is movable relative to the other, said sealing assemblycomprising: a groove formed in said one member, said groove extendingsubstantially transversely of the direction of movement of said memberrelative to the other member, said groove having a leading side wall, atrailing side wall, and a boittom wall extending between said sidewalls; a seal blade received in said groove, said blade having a tipportion projecting from said groove with a working surface definedthereon for sliding, sealing engagement with a surface of said othermember, said blade having a trailing side surface extending from thetrailing edge of the outer tip portion and disposed in opposedrelationship to said trailing side wall of said groove; said bladehaving a leading side surface extending from the leading edge of saidouter tip portion and disposed in opposed relationship to said leadingside wall of said groove; said trailing side wall of said groove beingformed with a convex ramp portion adjacent the open end of said groove,and said trailing side surface of said blade being formed with an upperconcave portion having a radius of curvature larger than the radius ofcurvature of said convex ramp portion such that forces urging thesurface of said concave portion into contact with said convex rampportion produce reaction force components between said concave andconvex portions that urge said blade to extend from said groove.
 9. Asealing assembly for providing a sliding seal between two members, oneof which members is movable relative to the other, said sealing assemblycomprising: a groove formed in said one member, said groove extendingsubstantially transversely of the direction of movement of said memberrelative to the other member, said groove having a leading side wall, atrailing side wall, and a bottom wall extending between said side walls;a seal blade received in said groove, said blade having a tip portionprojecting from said groove with a working surface defined thereon forsliding, sealing engagement with a surface of said other member, saidblade having a trailing side surface extending from the trailing edge ofthe outer tip portiOn and disposed in opposed relationship to saidtrailing side wall of said groove; said blade having a leading sidesurface extending from the leading edge of said outer tip portion anddisposed in opposed relationship to said leading side wall of saidgroove; cooperating convex and concave cam surfaces on said trailingside wall of said groove and trailing side surface of said blade,respectively, operable in response to forces urging said trailing sidesurface into contact with said trailing side wall to produce reactionforce components urging said blade to extend having upper and lowersurfaces, the lower surfaces being relieved inwardly with respect to theupper surfaces.
 10. A sealing assembly for providing a sliding sealbetween two members, one of which members is movable relative to theother, said sealing assembly comprising: a groove formed in said onemember, said groove extending substantially transversely of thedirection of movement of said member relative to the other member, saidgroove having a leading side wall, a trailing side wall, and a bottomwall extending between said side walls; a seal blade received in saidgroove, said blade having a tip portion projecting from said groove witha working surface defined thereon for sliding, sealing engagement with asurface of said other member, said blade having a trailing side surfaceextending from the trailing edge of the outer tip portion and disposedin opposed relationship to said trailing side wall of said groove; saidblade having a leading side surface extending from the leading edge ofsaid outer tip portion and disposed in opposed relationship to saidleading side wall of said groove; cooperating cam surfaces on saidtrailing side wall of said groove and trailing side surface of saidblade operable in response to forces urging said trailing side surfaceinto contact with said trailing side wall to produce reaction forcecomponents urging said blade to extend from said groove, said camsurfaces comprising a convex surface on said trailing side wall and aconcave surface on said trailing side surface, said concave surfacehaving a larger radius of curvature than said convex surface such thatthere is a substantial line contact engagement between the trailing sidewall and trailing side surface, further including a pair of cylindricalcoupling seal recesses formed in said one member at opposite ends ofsaid groove, a coupling seal member received in each said recesses, saidcoupling seal members each having a cylindrical body rotatable in therespective coupling seal recess, a groove formed in said body anddisposed coextensively with the groove in said one member and receivingan end portion of said seal blade, and means interengageable betweeneach of said coupling seal members and said seal blade operable to urgesaid coupling seal members to project axially from the respectivecoupling seal recesses and to simultaneously urge said apex seal bladetoward a centered position in said groove and to extend from saidgroove.
 11. A sealing assembly for providing a sliding seal between twomembers, one of which members is movable relative to the other, saidsealing assembly comprising: a groove formed in said one member, saidgroove extending substantially transversely of the direction of movementof said member relative to the other member, said groove having aleading side wall, a trailing side wall, and a bottom wall extendingbetween said side walls; a seal blade received in said groove, saidblade having a tip portion projecting from said groove with a workingsurface defined thereon for sliding, sealing engagement with a surfaceof said other member, said blade having a trailing side surfaceextending from the trailing edge of the outer tip portion and disposedin opposed relationship to said trailing side wall of said groove; saidblade having a leading side surface extending from the leading edge ofsaid outer tip portion and disposed in opposed relationship to saidleading side wall of said groOve; cooperating cam surfaces on saidtrailing side wall of said groove and trailing side surface of saidblade operable in response to forces urging said trailing side surfaceinto contact with said trailing side wall to produce reaction forcecomponents urging said blade to extend from said groove, said camsurfaces comprising a convex surface on one of said trailing side walland trailing side surface, and a convex surface on the other of saidtrailing side wall and trailing side surface, said convex surface beingformed on said trailing side wall and said concave surface being formedon said trailing side surface, said concave surface having a largerradius of curvature than said convex surface such that there is asubstantial line contact engagement between the trailing side wall andtrailing side surface, and further including a pair of cylindricalcoupling seal recesses formed in said one member at opposite ends ofsaid groove, a coupling seal member received in each of said recesses,said coupling seal members each having a cylindrical body rotatable inthe respective coupling seal recess, a groove formed in said body anddisposed coextensively with the groove in said one member and receivingan end portion of said seal blade, and means interengageable betweeneach of said coupling seal members and said blade operable to urge saidcoupling seal members to project axially from the respective couplingseal recesses and to simultaneously urge said apex seal blade toward acentered position in said groove and to extend from said groove.
 12. Anassembly as claimed in claim 11 wherein said last named means comprisesa pair of coupling seal cam surfaces formed on said seal blade, and aseal blade pressure member formed on each of said coupling seal members,said seal blade pressure members each being engageable with one of saidcam surfaces in response to rotation of the respective coupling sealmembers in their respective recesses.
 13. An assembly as claimed inclaim 12 wherein each of said coupling seal members has an outer endwith an upper contacting surface for sliding sealing engagement with asurface spaced from each of the respective ends of said one member, anda lower relieved surface inclined away from said contacting surfacetoward the respective recess.
 14. An assembly as claimed in claim 13wherein said coupling seal cam surfaces are formed on the leading sidesurface of said seal blade, and wherein said coupling seal members areeach formed with an extension arm projecting from said cylindrical bodyalong the leading side surface of said seal blade, said seal bladepressure member being formed on said extension arm and engageable withone of said coupling seal cam surfaces.
 15. An assembly as claimed inclaim 14 wherein the outer ends of said seal blade each has upper andlower surfaces, the lower surfaces being relieved inwardly with respectto the upper surfaces.
 16. An assembly as claimed in claim 15 whereinsaid one member comprises a rotor for a rotary engine or the like. 17.An assembly as claimed in claim 16 wherein said rotor has at least oneapex portion, and wherein said groove is formed in said apex portion.18. A sealing assembly for providing a sliding seal between two members,one of which members is movable relative to the other, said sealingassembly comprising: a groove formed in said one member, said grooveextending substantially transversely of the direction of movement ofsaid member relative to the other member, said groove having a leadingside wall, a trailing side wall, and a bottom wall extending betweensaid side walls; a seal blade received in said groove, said blade havinga tip portion projecting from said groove with a working surface definedthereon for sliding, sealing engagement with a surface of said othermember, said blade having a trailing side surface extending from thetrailing edge of the outer tip portion and disposed in opposedrelationship to said trailing side wall of said groove; said bLadehaving a leading side surface extending from the leading edge of saidouter tip portion and disposed in opposed relationship to said leadingside wall of said groove; cooperating cam surfaces on said trailing sidewall of said groove and trailing side surface of said blade operable inresponse to forces urging said trailing side surface into contact withsaid trailing side wall to produce reaction force components urging saidblade to extend from said groove, further including at least onecylindrical coupling seal recess formed in said one member at one end ofsaid groove, a coupling seal member received in said recess, saidcoupling seal member having a cylindrical body rotatable within saidrecess, said body haaving a groove formed therein and disposedcoextensively with the groove in said one member and receiving an endportion of said seal blade, further including means engageable betweensaid coupling seal member and said seal blade operable to urge saidcoupling seal member to project axially from said coupling seal recessand to simultaneously urge said seal blade toward a centered position insaid groove and to extend from said groove.
 19. An assembly as claimedin claim 18 wherein said last named means comprises a coupling seal camsurface on said seal blade, and a seal blade contact member on saidcoupling seal member, said seal blade contact member being engageablewith said coupling seal cam surface in response to rotation of saidcoupling seal member with respect to said recess.
 20. An assembly asclaimed in claim 19 wherein said coupling seal member is otherwise outof contact with said seal blade when said seal blade contact member isengaged with said coupling seal recess.
 21. An assembly as claimed inclaim 20 wherein said seal blade contact member is formed on the leadingside wall of the groove in said coupling seal member, and said couplingseal cam surface is formed on the leading side surface of said sealblade.
 22. An assembly as claimed in claim 20 wherein said coupling sealmember is formed with an extension arm projecting from said cylindricalbody along the leading side surface of said seal blade, said seal bladecontact member being formed on said extension arm, and said couplingseal cam surface being formed on the leading side surface of said sealblade.
 23. An assembly as claimed in claim 22 wherein said coupling sealcam surfaces are formed on the leading side surface of said seal blade,and wherein said coupling seal members are each formed with an extensionarm projecting from said cylindrical body along the leading side surfaceof said seal blade, said seal blade pressure member being formed on saidextension arm and engageable with one of said coupling seal camsurfaces.
 24. An assembly as claimed in claim 23 wherein said couplingseal member has an outer end with an upper contacting surface extendingto the end of said extension arm for sliding engagement with a surfacespaced from the associated end of said one member, and a lower relievedsurface inclined away from said contacting surface toward the respectiverecess.
 25. An assembly as claimed in claim 24 wherein the leading sidewall of the groove in said one member is convex and the leading sidesurface of said seal blade is concave.
 26. An assembly as claimed inclaim 25 wherein said seal blade contact member engages said couplingseal cam surface at a point spaced from the substantial line contactbetween said trailing side surface and trailing side wall on theopposite side thereof from said bottom wall of said groove of said onemember to thereby urge the edge of the leading side surface of said sealblade adjacent said bottom wall to engage said leading side wall of saidgroove in said one member with a substantial line contact.
 27. Anassembly as claimed in claim 26 wherein said cam surfaces comprise aconvex surface on one of said trailing side wall and trailing sidesurface, and a concave surface on the other of said trailing side walland traIling side surface.
 28. An assembly as claimed in claim 27wherein said convex surface is formed on said trailing side wall andsaid concave surface is formed on said trailing side surface.
 29. Anassembly as claimed in claim 28 wherein said concave surface has alarger radius of curvature than said convex surface such that there is asubstantial line contact engagement between the trailing side wall andtrailing side surface.
 30. An assembly as claimed in claim 29 whereinsaid convex surface extends from the outer edge of said groove oppositethe bottom wall thereof, and said concave surface extends from thetrailing edge of said tip portion, and wherein said trailing side wallhas a concave lower portion extending from said convex surface towardsaid bottom wall, and said trailing side surface has a lower convexportion extending from the lower edge of said concave surface.
 31. Anassembly as claimed in claim 30 wherein the working surface of saidouter tip portion has a leading portion and a trailing portion and animaginary rake angle line intersects said tip portion such that theleading portion of said working surface is on one side of said rakeangle line and the trailing portion of said working surface is on theother side of said rake angle line, said leading portion having acurvature the radius of which has a center located substantially on saidrake angle line, said trailing portion having a curvature the radius ofwhich has a center located on the leading side of said rake angle line,the radius of curvature of said trailing portion being larger than theradius of curvature of said leading portion such that the trailingportion of the working surface extends further from said rake angle linethan the leading portion of said working surface.
 32. An assembly asclaimed in claim 31 wherein said rake angle line intersects the bottomsurface of said seal blade at a location closer to said trailing sidesurface than to said leading side surface, and wherein said rake angleline intersects the bottom wall of the groove in said one member at alocation closer to said trailing side wall than to said leading sidewall.
 33. An assembly as claimed in claim 32 further including at leastone passage extending through said seal blade having an opening in thetip portion on the trailing side of the trailing portion of the workingsurface thereof.
 34. An assembly as claimed in claim 33 furtherincluding a seal blade spring received in the groove of said one memberand biasing said seal blade outwardly with respect to said groove. 35.An assembly as claimed in claim 34 further including a coupling sealspring received in said coupling seal recess and biasing said couplingseal member to extend outwardly from said recess.
 36. An assembly asclaimed in claim 35 wherein said seal blade spring has a central portionthat rests on the bottom wall of said groove and a pair of spring armsextending upwardly and outwardly in opposite directions from saidcentral portion, and further including a pair of projections on oppositeends of said blade depending below the bottom surface thereof, thejunctions between said bottom surface and said projections being curved,and said spring arms being engaged with the respective junctions andhaving a curvature conforming substantially to said junctions.
 37. Anassembly as claimed in claim 33 wherein said one member comprises a sealblade retaining member.
 38. An assembly as claimed in claim 37 includinga rotor for a rotary engine or the like, said retaining member beingmounted on said rotor.
 39. An assembly as claimed in claim 38 whereinsaid rotor has at least one apex portion defined by said retainingmember.
 40. An assembly as claimed in claim 39 further including atleast one pair of oppositely extending side seal slots formed in saidone end of said retaining member.
 41. An assembly as claimed in claim 40wherein said rotor has an end face lying in substantially coplanarrelationship with said one end of said retaining member, at least onepair of side seal strips mounted within said end face, one end of eachof said side seal strips being received in a respective one of said sideseal slots.
 42. An assembly as claimed in claim 41 wherein a clearanceis maintained between the ends of said side seal strips and the walls ofthe respective side seal notches in said retaining member.
 43. Anassembly as claimed in claim 42 further including a pair of oppositelyextending side seal slots in said coupling seal member, each of saidcoupling seal side seal slots being positioned in alignment with arespective one of said side seal slots in said retaining member to forman extension thereof, the respective ends of said side seal strips beingreceived in the slots in said coupling seal members, and wherein aclearance is always maintained between the ends of said side seal stripsand the surfaces of the respective side seal slots in said coupling sealmembers in all positions of said coupling seal member.